Re: Applesoft and RESET

[dempson@actrix.gen.nz (David Empson)]

vladitx <vladitx@nucleusys.com> wrote:

> It's just that firmware is not initialising the SP after RESET. RESET
> catches few nested subroutines and that offsets SP each time. If you
> happen to write "CALL-151" when SP is below some threshold you'll get
> "?OUT OF MEMORY" and probably SP reinitialised. I found this bug
> because I test short routines in Monitor (excellent tool) and do RESET
> + "CALL-151" too much.
> 
> So, this is present on IIe and IIc. Too lazy to test on IIgs right
> now. But I wonder how it went unnoticed and unfixed for so much time.

The ROM 3 IIgs stack pointer is always FB after Ctrl-Reset, even if I do
CALL-151 and Ctrl-C a few times. (This is running the bare firmware - no
operating system loaded.)

This might be a bug in older firmware but it was definitely fixed in the
IIgs.

Which operating system are you using? I'm wondering if this problem is
specific to DOS 3.3 or something.

I don't have any 8-bit Apple II models handy so I can't do a test at the
moment. I do have a IIc (with "revision 0" UniDisk firmware) so I could
test that at some point. The IIe stopped working, unfortunately, and I
haven't got hold of a spare one yet to track down the fault.

-- 
David Empson
dempson@actrix.gen.nz